The amount of time children spend using screens, such as televisions and computers, on a daily basis exceeds recommended guidelines but those guidelines were drawn up at a time when tablets, cell phones and other mobile devices were not as present in everyday life. Unless you are Amish or a doomsday prepper, it is unlikely that the future will mean current screen time guidelines.

And how valid are they anyway? Yes, prolonged use of screens by children is associated with adverse physical and mental health outcomes, such as increased risk of depression and anxiety in adolescent girls, but that is epidemiological curve fitting based on surveys, not real data.

New findings from research in the Seychelles provide further evidence that the benefits of fish consumption on prenatal development may offset the risks associated with mercury exposure. In fact, the new study, which appears today in the American Journal of Clinical Nutrition, suggests that the nutrients found in fish have properties that protect the brain from the potential toxic effects of the chemical.

DNA molecules provide the "source code" for life in humans, plants, animals and some microbes. But now researchers report an initial study showing that the strands can also act as a glue to hold together 3-D-printed materials that could someday be used to grow tissues and organs in the lab. This first-of-its-kind demonstration of the inexpensive process is described in the brand-new journal ACS Biomaterials Science & Engineering.

A variety of wheat that is resistant to a destructive fungal disease has been found to have specialized and protective cell walls, according to research published in BMC Plant Biology. These insights could help to produce stronger, disease-resistant varieties of durum wheat for improved pasta production.

Researchers have determined that languages with a wide range of tone pitches are more prevalent in regions with high humidity levels while languages with simpler tone pitches are mainly found in drier regions.

They explain this by noting that the vocal folds require a humid environment to produce the right tone. That means climate and weather our voices too. 

Two teams of astronomers have used computer models to look back nearly 13 billion years, when the Universe was less than 10 percent its present age, to determine how quasars - extremely luminous objects powered by supermassive black holes with the mass of a billion suns - regulate the formation of stars and the build-up of the most massive galaxies.

Using a combination of data gathered from powerful radio telescopes and supercomputer simulations, the teams found that a quasar spits out cold gas at speeds up to 2000 kilometers per second, and across distances of nearly 200,000 light years - much farther than has been observed before.

Diabetes has been described as an epidemic of modern times so why does it affect aboriginal people more?

Over the past several decades diabetes has become a prevalent health concern among Canada's First Nations communities, but it wasn't always so.

Organic semiconductors are prized for light emitting diodes (LEDs), field effect transistors (FETs) and photovoltaic cells. As they can be printed from solution, they provide a highly scalable, cost-effective alternative to silicon-based devices. Uneven performances, however, have been a persistent problem. Scientists have known that the performance issues originate in the domain interfaces within organic semiconductor thin films, but have not known the cause. This mystery now appears to have been solved.